Nutritional facts
per each of 8 servings: about

Method

Slice 1 of the onions; set aside. Finely chop remaining onion.

In slow cooker, combine chopped onion, lentils, half of the tomatoes, the jalapeño pepper, garlic, ginger, half each of the cumin seeds and coriander and 6 cups water. Cover and cook on low until lentils are tender, 8 to 10 hours.

Using immersion blender, purée mixture to desired consistency and thickness, leaving some lentils whole. (Make-ahead: Refrigerate in airtight container for up to 24 hours or freeze for up to 3 weeks; reheat before continuing with recipe.)

Stir onion mixture into slow cooker. Serve dal with yogurt, cilantro and remaining tomatoes.
Tip from The Test Kitchen: If you don't have an immersion blender, add one-third of the lentil mixture to a blender, purée until smooth and then stir the purée back into the slow cooker.